1. Field of the Invention
The present invention relates to electronic calculators used for tabulating a total sum of money. More particularly, the present invention pertains to those electronic calculators having coin push buttons dimensioned to have a diameter substantially equivalent to the diameter of a particular coin denomination and used to increment a displayed number by the value associated with that particular coin denomination.
2. Description of the Prior Art
Devices for the tabulation of money have been proposed for specialized purposes, e.g., education or balancing a checkbook. Electrical calculators designed for the purpose of tabulating money include desk top units or portable units small enough to fit into a checkbook. Mechanical devices for the tabulation of money include games, calculators, cash registers, and others.
U.S. Pat. No. 4,959,017 issued Sep. 25, 1990 to Barbara J. Thompson et al discloses an electronic calculating device for teaching user of the device how to handle money. The device has several programs to provide a variety of question and answer sessions to the user.
U.S. Pat. No. 4,308,588 issued Dec. 29, 1981 to John T. Siwula discloses a portable calculator for balancing a checkbook. One of the features of the device allows tile user to key-in a monetary amount and perform a "trial balance" operation which updates the remainder of the user's balance for each entry.
U.S. Pat. No. 3,488,864 issued Jan. 13, 1970 to Catherine T. McManus discloses a mechanical device for improving the monetary skills of the user. The device is designed to receive ten pennies located above two nickels located above one dime.
U.S. Pat. No. 4,571,189 issued Feb. 18, 1986 to Spencer L. Shank discloses a board using overlays having a predetermined number of printed coins thereon for allowing a user to count the printed coins and associate a predetermined number of coins with another single coin or paper bill printed thereon.
None or the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.